Some Troll gear has been datamined so that's there for sure. I highly doubt the Corrupted Ashbringer is ever going to make it in anything other than the black market AH. I'd assume the old blacksmithing weapons you can't get anymore will be there as well.

I wonder if the forge is related to the next stage of the legendary quest. It would be cool if the server had to work together to unlock something but at the same time you have to be mindful of low pop servers getting left behind.

Those are just greens that will be dropping in the zone. I wish I could find the blue post that was talking about it. But there are some patterns like the lionheart blade and it's upgrades that should be coming back as well as some gear that got removed from questlines and such.

//edit: Well I can't find it..but they are BOE greens with random stats for xmog. It is possible that those can be crafted or zone drop. But I personally think there are other patterns and weapons that should be put back on the crafting table